For a method for determining a touch point adopted by an existing surface-capacitive touch panel, a part of charges is absorbed by a finger from the touch point, so as to form a very tiny current consisting of four sub-currents. A size of the sub-current flowing through one of four corner electrodes is proportional to a distance from the finger to a corresponding corner. Through accurately calculating a ratio of the four sub-currents by a controller, it is able to determine a position of the touch point.
However, the calibration in this method is complex and it is required to eliminate electromagnetic interference (EMI). In addition, this method does not support multi-point touch.
Currently, the multi-point touch may be achieved by a mainstream projection-type capacitive panel. However, due to a series of defects in design and process, the touch point is susceptible to the external environment and thereby easily drifted. Although the interference may be eliminated by some mature algorithms, the overhead of a processor will be increased.